Closed-hopper sand-blast.



Yatented Sept. 23, 1913.

G. P. STEEDMAN. CLOSED HOPPER SAND BLAST. APPLIOATION rum Nov.2z,1912.

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GEORGE F. STEllLDMAN, Olli" ST.

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110 UIS, MISSURI.

Specification of Letters Potent llutcntcd iiieiulz. Ltl, lil itt.

Application tiled 'November 213, 1012. Serial No. tmtli.

To all 1z0/omit m ay/ concern Be itltnown that l, 'Grenen F. S'rnnnmum, a citizen ot the United States, residing;l at St. Louis, Missouri, have invented a certain new and useful Improvement in Closed- Hopper Sand-Blasts, ot' which the following,r is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

Thisinvention relates, to closed hopper sand blasts oit' the type illustrated and described in myv prior Patent No. 979,897,

l dated December V27', 1910.

Une object of my present invention 'is to provide a sand blast of theY type referred to in which a single mechanism 1s provided for `sg'tnferning the sand-gate or valve that muti-ois the supply of sand to the mixing' chamber and the shut-ott' valve or throttle alve that governs the Supply of sand and fluid pre une to the blast tool, und another object is to provide a 'closed hopper sand blast apparatus ot' simple construction which is so designed that the parts which are subjected to the greatest Wear can he replaced easily and Without the necessity ot' cutting rivets or other permanent fastening devices.`

The figure ot' the drawings is a vertical sectional View of a sand blast apparatus constructed in accordance with iny invero tion. f

.Referring to the drawings which illustrate the preferred -form oil my invention, A designates the closed sand supply hopper, 1? designates the Inixing chamoer, and 1 designates the sand-discharge opening through- Which the sand flows from the supply hopper into the mixing chamber. A shut-ott valve or throttle valve U, preferably et' soft mbber, is arranged in the mixingr chamber so to enable the flow of sand und air through the hose i3 'ihet leads to the blast tool, not shown, to 'ae ".opgu'd and started instantly at the will ie o; it and a suiudqgate o1.' vali "fr i regulatirug the flou' olf i nd from the supply hopper .il into the mixing chmul) r il. T sand-gate or Avalve l), is combine a". si.

t 'with the throttle valve C oo as to .nahle a tingle actuating mechanism to be used for control ling both of said valves and ateo tor einniingv connnunicution between the sund .sup-- [lily hopper and the niixingf; chamber to he cuty oil automaticfllly whenever the throttle vulve (l is closed. ln the nieliurel form o't' my invention, as herein shown, the sand- `gite l) is dcinglmhly connected by means ot' removable tin-:lening devices l lo a castiner it that marries the 'throttle valve C, and said' plate is arming-ed in such u' manner that it bears against und slides upon the top wall ol the mining chamber 'iw'. Any suitable mechanism can he used lor actuating.; the connected valves und l), the mcclninism herein shown conf-cistiinr o't a mannaily-operaied lever 5 `provided with a spring-prcsscd rotelmt (i that cooperates with a ratchet plate l" and links 8 and a connecting har J `t'or transmitting move Ameot from the lever 5 to the rod or stem l() ot the throttle vulve l, said rod prt jecting through a slntlinu'hoi: Ai l. in the end Woll of the mixing; chzunber. ily manipulatini;r the lever ii the sand-fate l) can be arranged in different positions giving a greater or .less opening for the sand. so as to accurately control the flow of sand from the supply hopper A into the mirino' chamber, and when said lever is moved far enough to close the throttle valve C, as shown in the drawing, the Saud-gale or valve l) will have previously completely closed .the sami-discharge opening in the bottom oi' the hopper and thus. cut oil" oommunication between the hopyer A and the mixing' chamber ll before the valve C closes its cooperating opening'. The pawl and ratchet mechanism that cooperates with the lever 5 operates to hold the valves C and D in closed position. .it stop 7'L which is udjustahly mounted in an elongated slot in the ratchet plate 'i acts as a stop to limit the outward movoulent of arm 5 and so controls the opening: ot' valve lf) und the volume ot' sund 'nasa' 1g into ruininglr chum her. fin view of the 'it that the sand-gute or valve 'll :wronged above the throttle valve (fl and .closes in advance ot" same, said valve D protects the throttle valve and prevents .it from heine' subjected to constant abrasion by the sancl that flows from the supply hopper into the mixing chamber, thereby ,greatly prolonging the life of the throttle valve C which is usually made of l between the throttle valve and the sleeve 2 to which the hose 2 is. connected.

In addition' to the desirable `features above-mentioned Suche construction is in-- expensive to manufacture and can be maintained at a lowcost in view of the tact that the part which is subjected to/t-he greatest wear or abrasion from the sand, namely, the sand-gate D, consists of aA small piece of sheet metal that is detachably connected to the throttle casting 4 in such a mannerthat it can be renewed easily. The throttle valve C is preferably made of soft rubber and is removably carried' on casting a' so that it can be renewed readily. 1 also prefer to arrange a removable bushing 1 in the top wall of the mixing chamber B, forming the sand-discharge opening that establishes' communication between the supply hopper and the `mixing chamber, thereby enabling this part to be renewed easily when 'it becomes worn.

The filling hopper E .which is arranged above the sand supply hopper A is provided with an opening through which the sand ows into the supply hopper A, and a valve F is provided for normally closing said opening so as to outl oli communication between the iilling hopper E and the supply hopper A. The bottom of the filling hopper E is formed by a member 12 permanently connected to the side walls -or the hopper E and a removable member 13 in which vthe outlet opening of the filling hopper is formed, said removable member 13 preferably consisting of a substantially funnel-'shaped casting that is clamped between the bottom member 12 of the filling hopper and a ring 14: on the top wall of the sand supply hopper A in such a manner that it can be removed easily by simply removing a few nuts or bolts that connect the bottom member 12 of the filling hopperv to the ring 14 on ,thev supply hopper 'A. In the iihmof my invention herein shown-"the 'removable member 13 is provided at its upper end 'with a laterally pro# M jec'tinp; horizontal flange 13 that lies between the parts 12 and 14, and screw-threadedjpstuds 15 provided with 'nutsl'L are used Lt'orl connecting` said parts together and thus clan'ipinp; themember 13 in operative position, vit being preferable to use" a piece of packing; 1G between the under side of the meniber 1B and the ring 1t on the hopper A so as to insure an air-tight joint. rlhe valve' F is substantially cone-shaped. and tits in a tapered seat formed in thelower end oi' the removable member 13,.said member 13 being provided at its lower end with a depending flange or skirt 16 of some suitable flexible or pliable material which is pressed against the valve F by the pneu- ,matic pressure, in the supply hopper ,'thus y insuring a tight joint. Any suitable means may be. used for actuating the valve F, the

means herein shown .consisting of a mannally-operated-rock shaft 17 provided with an arm 18 that is connected 'by means of links 19 to the valve F. l l

Having thus described my invention, what elaim as new and desire to secure by Letters Patent is:

1. ln a sand blast. ap aratus, a sand /supf ply hopper, a mixing c amber communicatmg with said hopper and provided with adi'scharge opening, a throttle valve in said mixing chamber for closing said discharge opening, and a sand-gate or valve for regulating the dow of the sand trom the suppl hopper into the mixingehamber, said-san gate being arranged between the throttle valve and the opening through which the sand enters the mixing chamber so as to protect the throttle valve in the mixin chamber from abrasione caused by the san flowing into the mixing chamber as the throttle valve is closing. i i

l 2. 1n a sand blast apparatus, a sand supply hopper and a mixingI chamber connected together by means of an opening, a conduit leading from said mixing chamber, a throttle valve in said mixing' chamber orclosing said conduit, and a dplate arranged above.

said throttlevalve an detaehablyv connected '.to` same for controlling the flow of sand through the opening that establishes oommunication between the supply hopper and the mixing, chamben 3. In a -sand blast apparatus, a mixing chamber provided in itsf..top wall with va receiving,- opening and 'in one of its end 'walls with a dischargeV opening, a. throttle valve in said mixing' chamberprovided with a non-metallic end portion for cuttin o' ply hopper having a top wall, a ring per- In a sand blast apparatus, a, sand sup@ seq l the escape of the material through sai dis- 4 `charge opening.,

manently connected to said topvwall, a tilling hopper arranged above same and provided at its lower end with a casting, means for detachably connecting said casting to said ring., and a removable member clamped between said'castinzgr and ring and provided with an openingthrough which the sand flows 'from the filling hopper into the supply hopper.

5. ln a closed hopper sand blast, a sand hopper, a removable mixing. chamber detachably connected to the lower; portion of the sand hopper, the sand hopper being provided with a sand opening that estab-- lishes communication between the sand hopper and the top of the mixing chamber and the mixing chamber being provided with a discharge opening to which the hose is c0n nected, a sliding member to Which/ay gate isy connected that coperates withf'the sand opening and regulates effective `opening of the sand opening, and a flexible plug or Valve carried by said sliding' member thatV coperates with the discharge o ening in the mixing chamber and serves to ose said discharge opening against the passage of air and sand or open same as may be desired, said gate being so arranged on the sliding vmember with relation to the said lug or valve that the gate-'will com letely ose the sand opening before the p ug reaches the discharge opening in the mixing chamber. f 1E `In testimony whereof I hereunto affix my signature in the Igresence of two Witnesses, this 16th day of ovcmber 1912. GEORGE F. `STEEDMAN Witnesses:

R. E. WINiiLnR, LEON S. BUCKLES. 

